Cement improver and method



"306. cowosmons.

"COATING R PLASTIC.

Patented July This -$invention relates to material having lubricating properties and coacting to or eliminate voids in cementitious materials.

This invention has utility when used alone for its flow promotion properties, or when incorporated in mixes of cementitious material. In water it has a smoothness to draft as coating or spreading on hard material, while in mixes it promotes fluidity with properties of easy working, m as wall coatings and floors or pavements. The

property of easy working is attributed to its controlled quantity of moisture carried by the magnesium hydrate. In some instances, when desired, this magnesium hydrate may be supple- ,15 mented by hydrous aluminum silicate. This material when produced, as herein disclosed, from dolomite, has quick setting as responsive for minimizing working in the production of the desired surface; quickening curing time, giving less 20 out-of-service time for roads and bridges, or for the work to be used. A factor to this end is be- "lieved to be the carbonate and its speeding up cooperation in crystallization reaction. This material has increased hardness, making more resistant to earlier use; increased strength, promoting use of lower factor of safety; reduced volume change in setting to an extent eliminating cracking or fractures from such cause. It has the capacity of holding or adhering to the 30 constituents, which in the concrete mix results in holding the coarse aggregate against segregation. The composition makes the dry finished material of plastic mortar or concrete cement more white; and gives the material a density of body for effective water-tightness.

Special value is obtainable in the operations as herein conducted. By this peculiar or special attention, the range of utility and the definite- The material as quarried hereunder, may, to

an advantage, be a calcium rock carrying 30 r cent f manesium carEonate and usfiy erme ami. l reducedby crushingmseparated for sizes preferably 5 by screening. The stone may run over seven inches and under eleven inches. This stone is introduced into an upright or shaft kiln and given .the heat treatment or kiln burning, preferably in a range between 900 and 1000 C. for say four 150 hours. dol in Northwestern Ohio and used, applicant has found, .under this'treatment becomes inert or inactive .to water of hydration as to the magnesium oxid. The flow of CO: from the kiln is measured and 55 when the records show such gas how to drop to 2,048,967 CEMENT IMPBOVEB AND METHOD (llarencehltex l'oledo, Ohio No Drawing. Application March 21 1932, Serial No. 600,384

llClalms. (01.1w)

man

ness of control are more accurately determined.

F Ex Cross Reference amme PATENT OFFICE .1873, theburnedlimefromthekilnis drawn out upon a conveyor and graded by hand picking. The hand picking process removes all overburned material and also the underburned material.

The residual product, after having had the over- 5 burned and underburned portions removed, is then massed and sampled and the refractive index determined. The extent of this burning, which is quite uniformly conducted, is run desirably to give refractive index between 1.5 and 1.7 when the refractive index of the raw dolomite was about 1.4. Additional physical identification for this extent of burning is found in the decreased conductivity which in instances have brought about a change of from 880 to 1200 and in ,direct proportion to the temperature and time of heating. The specific gravity is also reduced over the time interval, say in heating at 950 C.,-wherein after forty-five minutes, the powder may have a specific gravity of 3.29; after four hours, the specific gravity arose to approximately 3.50. This is a ready check method for determining the extent to which the carbon dioxid has been driven oif-from the rock. In practice it is denimble hereunder that by weight there be. re- .tained between 5 and '7 per cent of the raw carbonate, which in the use of the product speeds up crystallization reaction for rapid setting.

This calcined material is bdivided, preferably by hammer'mill, to pass eve having ,1 its mesh ten to the inch, and is now ready for the -rpeeial'hydration; conducted to impart the controlled water properties for the desired .degree of plasticity. The liquor for the hydration hereunder is -charged or carries in solution, ma esium chloride preferably, although a chloride of less calcium for chlorine may be adopted, as a strontium chloride or aluminum chloride. 0 The proportion of this ma esium chloride should not be in excess of 1E7, o; Hie magnesium oxidcontent. This hydration liquor"at"a"'fimmum preferably between 12 and 20 C. is -supplied to the sub-dividedpredominantly-oxid 5 i1 a1kaline -earth material while the material is at a temperature between 60 and 65 C. The. liquor is preferably not flooded upon the material but -is delivered asafine sprayon the material while the hydratoris operatingto move the material. The spray is in such excess and there is such freedom for conducting ofi heat that in the exothermic reaction the material shall be held .down against any marked rise above the boiling point of water in .theopen, and in practice this am-has. a e

is kept down not to exceed 105 C. for obtaining 18.3 pounds of water and the hydration approxibetter results hereunder. mates:

This hydration reaction produces magnesium Pounds hydrate which, desirably, may be in the range up Magnesium oxid 22 5 to of the entire solid mass by weight. This Calcium hydrate 40 magnesium hydrate has great avidity for water Calcium chloride 3 i and will readily take on and hold ten to fliteen Calcium carbonate 6 times its own weight of water. In keeping the Magnesium hydrate 1 proportion of magnesium hydrate low there is 10 minimized tendency for shrinkage, such as might form hair lines in a wall. when it is desired to promote plasticity by carrying additional moisture and keeping the magnesium hydrate pro- 5 portion down, or lowering the magnesium hydrate 1 content this can be done by reacting upon the acid radicals than has the magnesium herein magnesmm even though. It be ,Pemgastii This reaction as conducted hereunder accordingly .W drous aluminum Smcate L- -r m 8 brings about a transfer or interchange of the of smca i i g gg ig i ii g zg chlorine from the magnesium chloride and the a p that, collateral to the magnesium hydrate, there calcmm' bmught abmt dmng the dration; that is in the presence of moisture, calis possible here the introduction of additional 0mm carbonate, and magnesium oxid The g gz g g capagity gg fi fi times by nesium oxid is inert to the hydration reaction, o i :3 ac to te ;due to the time factors in the heating treatment reac on s mm one wo nu S .hereunder. This magnesium oxid accordingly and as the reaction proceeds a rapid rise in temdoes not react with the magnesium chlorid but perature occurs to 96 to 99 slowing up with does react with the calcium to form calcium final rise to 100 to 102 C., which converts the g excess of water not combining in the reaction 2 :3 5 Sgt ggg igggssg a zsi g gg g gi gg into steam Y which is rapidly removed from hydrate radicals to be taken up by the magnesium the hydratmg mass- The operation requires as the calcium takes on the chlorine Ca(OH)z about fifteen minutes to complete, resulting in a 'fiplus Mgch equals each plus Mgwfin In the dry During the progressing proportions as hereinbefore set forth, it is deof this hydratlon as practically completed sirable to have the magnesium hydrate to be not there is an addition made or 215% 5% of this in excess of 20% of the magnesium oxid of the hydration liquor to the charged mammal? or other :residue of this hydration reaction. The dolomitic a such as moisture'laden atmOSDhETe is oxid, in this hydration as herein conducted, as to provided to maintain this excess of humidity; the calcium may meet up to the chemical and the Product is Placed in storage for thor' equivalent of the magnesium chloride used, com- ,ougmy digesting i seaming or. oompleting the -plete conversion thereof to the calcium chloride, 40 hydration operatlon- This Period may while the magnesium oxid in the presence of this tageously run about fourteen days with calcium has not undergone the hydration change. Volume increase therefrom running frequently The special calcining is conducted to impart to greatfir- .the magnesium oxid, a form resistant to direct The quantity of water smutlon d the .hydration although susceptible to reaction with P ranges between 25% and 30% of the total silica and alumina. There is, accordingly, here- Weight of the Oxids- The ammmt water under provided a definite controllable reaction a y Combining, T811865, between 15175??? and 16% as to the incorporation oi zero percentage and in the first reaction. Du the digesting .upward of magnesium hydrate into this hydraaction any free moisture rema n n i t Product -tion material. All or a fraction of the calcium is combined, givin a co water o about hydrate may be changed to calcium chloride. 18%. This digest on'r fl E olfundel 8 Magnesium hydrate is excessively buttery or temperature ra from to finally smooth in its qualities or properties with water. falling to below 44 C. which shows dige t Due to the establishment of the periclase or be omp t d. T s u sta containing m resistant state for the magnesium oxid, there is 55 885mm hydrate 15 produced i 8 i-d State not efiected herein the Sorel cement reactions:

and brought to a dry state by its own eat of reaction. This more or less crumbly mass is then Mgch plus mmo a1 3M sub-divided by grinding in a humid atmosphere as equ s goMgClzAqw in the presence of steam or water vapor, and is --5MgO plus MgCh plus 171-120 in condition for packaging and transporting or I v equals 5MEOMgC12Aqn "storing for use.

. 'This oxychloride product is not a result hereg 5 22 223333 2; 1%? i g g z gi% az :under, because there is not suiiicient concentraand 56 lbs calcium'carbonate Eliminatin de- -tion of the magnesium chloride but applicant duction Over and under) i g the resin or produces the magnesium hydrate and calcium the calcininghere chloride. The temperature of the reaction is one precluding the formation of magnesium chlorid This is the dry powdered material of commerce, which may be combined as an improver in cement operation.

Reaction to produce magnesium hydrate The calcium as herein has a greater aihnity for Pounds V in, the presence of the calcium hydrate and there g ig f fi g g I a "is thus theiormation of calcium chlorid. This and say f" means there is not any production of oxychlorid, Calcium carbonate"";; 6 even of magnesium or calcium. The degree of concentration hereunder as disclosed is not high,

Hydra-ting with 12% magnesium chlgrigs as to ;running from 17 to 27 per cent as to anhydrous the total of magnesium oxid, ere s use about jmagnesium chlorid. Furthermore, an oxychlorid 2 lbs. of magnesium chloride to approximately is not formed in the presence of calcium hydrate. 75

106. cowosmous,

COATING OR PLASTIC.

Additional control ior the resultant material may be obtained by'incorporating in the liquor .of hydration, boric acid of a borate. This boric --acid is likewise seized upon by the calcium as against the magnesium in the hydration opera- "tion, with the result that there is produced a calcium borate. The proportion of the borate is preferably not in excess of by weight of the calcium oxid of the calcined .material before hydration. I I Solubilities I The borate and hydrates as produced here- 'under, aswell as oxids and carbonates, are relatively insoluble or diiiicultly soluble in water, while the calcium chorlide is most readily soluble. The hydrogen is colloidal.

,Leach,ing For certain materials, this calcium chloride may be readily leached or washed out of the mixture. For other purposes, it may be desirable to leave this calcium chloride in as it possesses especial value for plastic material operations say below 0 C. Furthermore, it is an incorporated additional water affinity or hygroscopic agent permeating the mass so controllably dominating the "setting that there is not material tendency for shrinkage or the development of shrinkage occurrence in setting. Again, especially in the borate combination, this chloride does not develop tendencies to eiiioresce, and thus leaves the material in acceptable shape when used as a brick or stone cement in laying up brick, stone, terr cotta, or other work.

Compounds the invention herein described has hydrate properties of plasticity, a great field of its usefulness is for gauging into other ingredients as "used in the 'various industrial processes of masonry and stone operations, as well as wall finishes. The material hereunder may beincorporated according to the character of the work to be done and may vary with the mixes. For instance, for concrete of l-1 -3 mix, this material maybe added to of the weight of the cement: wherein the cement is 1, the sand 1 and the broken stone 3 parts. when there is 'a 1-2-4 mix, this material may be 12% of "the weight of the cement. In a 1-2 V -5 mix, this material may be 14% of theweight of the cement. In a 1-3-6 mix, this material may be 16% -the'cement.

For mortar with 1 bag of cement there may be used 2 bags of the material hereunder and 3 parts by volume of sand. 1 a Y 'For stucco there may be used 1 bag of sand, 1 bag of the material hereunder and two bags of hydrate, with 2 parts of hair or hinder. 5 1

For scratch coat, there maybe, under the stucco formula, sand 3 parts to 1 of ,the stone; formula for brown coat, 3 parts to 1; finish coat, with no hair, but suchcoat to be sanded, there may be 3 to 4 parts of sand to 1 of the stucco 'combination'without the hair. r

For whitewash, to resist heat, there may be used 1 bag of cement to 2 bags of the material hereunder. V 1:

The magnesium hydrate hassuch a mobility cor freedom for flowing, that it effectively permeatesto'such an extent as to reduce'the voids of the weight of this substance when ,strengthof the mass is Cross Reference and to give a density in product effective in the anass or the product for. water tightness. Ac-

cordingly, as used for a gauged-in material, in ,cellar walls, cisterns, sewers, or other structures, there is a resultant wall effective for holding out or holding in the liquid against passing through such wall. This means that the wall structure itself accomplishes the end independently of a supplementalo'r additional treatment. There is utility in this for floor work and pavements wherein seepage material or liquids therethrough may be detrimental to building structures. This means also that the liquids as not passing therefrom have no tendency to leach out the elements and there is retention of unusual rigidity of ,structure hereunder. I When used as an improver for mortar, the thrown material from the trowel has a run or spread distance over the laid-up wall, for direct distribution at the throw in developing the desired thickness of such cement or mortar withput additional spreading with a trowel. In ce- ,ment operations, especially where towers or chutes are used, there is flow in the chute upon the work with a minimum of rise or a very low angle of repose, attributable to a great extent to the moisture carried in the mixture. This is a factor in economy in setting up towers and chutes for a range of operations.

7 Furthermore, in this running out of the material, it carries the uniform mix with it for it holds in suspension the aggregate, as well as sand and cement, when gauged in, say for even 5% as to the cement, although in practice, it may without detriment be run up to or 20% as to the cement. This is a factor in whitening the finished material. The holding of the aggregate in the putty means that tamping may be minimized or greatly reduced, for the aggre- .gate has not .a tendency to settle out, and the wall has the aggregate maintained uniform .throughout the structure even though the mixes be run for considerable depth at a time. This is .a property which tends to hold the aggregate even closed to the upper or outer surface of the cast. However, if there be occasion for finished trowelling or working, such may be completed with a minimum of labor. In the pouring there may be a float bar run or drawn over to gauge the ..top.suriace-ot thewet material, and within the course of an hour or an hour and one-half, ,whenthe material is approaching set, a practically once-over trowelling determines the finished surface.

ofthe mix is obtainable the cement or plastic material.

;Avoidance of this more free water excess means avoidance of washing away of cement or plastic material. reduction in thequantity of water-at the final .mixing is dueto the fact that ,thismagnesium hydrate thoroughly disperses itself in the mass for minimizing voids. ,The time forsetting or curing is reduced by I incorporated in a cement .plaster. It has-aquicker time for setting. The increased. It has a degree ofpermanency materially enhanced. It may, as itself, bemolded or cast intoslabs of a conasiderable degree of translucency, and the matecut, drilled, threaded and polished to form artificial marble.- As a wall or finish coating material, it has plasticity attributes as distin- ;S? $h ma ll f a u xaminer Modification While the raw material taken hereunder has in this instance been dolomitic, high calcium lime may be used. The specific gravity of this material runs about 2.4% which is slightly less than 8% below the specific gravity of the similar dolomitic material not given this treatment hereunder.

If a hydroxid product hereunder be ground with such severity as to produce a suiiiciently high temperature to liberate a part of the water of hydration, the resultant product will become non-plastic and fall below the 200 plasticity figure as determined on Plasticimeter described U. S. Bureau of Standards Technological Pape No. 169. On the other hand, by grinding this resultant hydro-chloro-boro-calcium-magnesium oxid in the presence of moisture vapor, test of the resultant product shows a plasticity factor of 250 or greater, and that a storage for ten months has failed to destroy this plasticity. Furthermore, this substance will make up into a plastic putty ready for use within two and onehalf hours.

As a lubricant material, this magnesium hydrate containing substance may be put into solution and used as a coating where the material is to move or have a drawing action which offers resistance, as in wire drawing operations. The hydrate hereunder has an alkaline reaction tending to clean, as well as lubricate in this treatment.

This magnesium hydrate herein has a degree of physical sub-division peculiarly identifying this product in that of the product hereunder may pass a theoretical 750 mesh per inch sieve, while 60% to 65% of this material may pass through a theoretical 1600 mesh per inch sieve. The basis for the used figures is that usual in laboratory practice of micron measurement through a microscope. This degree of subdivision is attributed to temperature control and the types of reaction conducted hereunder.

While, the magnesium chloride is suggested as the chloride for hydration liquor, the weakerthan-calcium chlorides may be used alone or in difl'erent combinations for producing limited definite percentages of the hydrates of strontium and aluminum within the mixture.

The control qualities of the material herelmder may be definite as to more or less magnesium hydroxide, as well as to the quantity of calcium chloride. This latter may be leached out entirely, partially, or left in as to a predetermined control quantity. This calcium chloride seems to have deflocculating properties improving the uniform suspension of different materials in the aggregate, even to supplement the colloidal properties of the hydrogel, when the latter is used. The cooperation hereunder may be considered as a keying providing projections as a sort of slip insurance which, as thus keying the various elements of the mix against shifting, not only holds the particle suspended in the aggregate for the set, but seems to be a factor in improving hardness. This advantage of the slip insurance is due to the finely disseminated particles approximating colloidal size. It also improves the hardness and the control rate of set. The calcium chloride as in the cast structure from this material seems to serve as a catalyzer, for it may be even leached from the finished cast without detracting from the physical strength and appearance thereof.

The calcium chloride is created in the medium What is claimed and it Letters Patent is:

1. The method of producing a cementitious material comprising calcining limestone to leave approinmately five to seven per cent thereof carbonate with calcium oxid to the extent burned 20 readily responsive to hydration, hydrating with a solution of a chlorid of less aflinity for chlorine than calcium amnity for chlorine. said solution being a water solution, and providing the water volume in such excess that the temperature of 25 hydration reaction does not exceed C., said is desired to secure by hydrating solution being dilute against forming an oxychlorid.

2. The method of producing cementitious material comprising calcining dolomitic rock to leave 80 approximately five to seven per cent thereof carbonate in association with reaction resistant mag- .nesium oxid and reactive calcium oxid, reacting thereon with a solution of magnesium chlorid and water, controlling the reaction to keep the 35 temperature from exceeding 105 C. and the chicrid to be not in excess of twelve per cent of the magnesium oxid to get a mixture of magnesium oxid, magnesium hydrate, calcium hydrate, calcium chlorid and calcium carbonate, and leaching to remove calcium chlorid therefrom.

3. The method of producing a self-hardening dry powder cementitious material comprising burning dolomitic limestone to magnesium and calcium oxld to such an extent that but a minor portion of its calcium remains calcium carbonate; sub-dlviding the material into granular form; and reacting to produce magnesium hydrate from said calcium oxid by hydrating the granular material with a just sufficient amount of solution containing a boric acid radical with 50 the calcium to obtain a dry powder.

4. The method of producing a dry powder ce- "mentitious material comprising burning dolomitic limestone in a range of 900 to 1000" C. for driving ofl carbon dioxid to such an extent that but a minor portion of its calcium remains calcium carbonate; subdividing the material into granular form; and reacting to produce magnesium hydrate from said calcium oxid by hydrating the granular material with a just sumcient amount -of solution containing magnesium chlorid to obtain a dry powder containing calcium chlorid, and leaching for obtaining predetermined reduction of the calcium chlorid.

5. The method of preparing a cementitious substance from dolomite comprising calcining dolomite at 900 to 1000 C. to an extent to retain 5 to 7 per cent carbonate, and hydrating with a chlorid solution, said hydrating solution includ- 70 ing a boric acid radical.

6. The method of preparing a cementitious substance from dolomite comprising calcining dolomite at 900 to 1000 C. to an extent to retain 5 to 7 per cent carbonate, hydrating with a chlo- 75 O M POSITIONS,

' COATING R PLASTIC.

rid solution, and reducing the calcium chlorid content thereof by leaching.

'7. The method of preparing a cementitious substance from dolomite comprising calcining dolomite at 900 to 1000 C. to an extent to retain 5 to '7 per cent carbonate, and hydrating with a chlorid solution, said hydrating solution including hydrous aluminum silicate.

8. The method of producing a self-hardening, dry powder, cementitious material comprising burning dolomitic limestone in a range of 900 to 1000 C. to magnesium oxid and calcium oxid to such an extent that approximately six per cent calcium carbonate remains, with the magnesium oxid resistant to direct hydration and the calcium oxid to the extent burned readily responsive to hydration subdividing the material into granular form, hydrating with approximately twelve per cent of magnesium chlorid as to the magnesium oxid from said burning to obtain from the added material of the hydration approximately onefourth as much magnesium hydrate as said carbonate from the burning, as much as one-half calcium chlorid as to such carbonate with stability for the magnesium oxid and calcium carbonate, said hydration being conducted against the production of oxychlorid at .a rate to keep the temperature of hydration against rising above 105 C. and the quantity of the water of said hydration approximating thirty per cent of the total weight of the oxids from the burning, and allowing said mass as hydrated to digest for the temperature to fall to approximately C. in forming a dry mass retaining approximately onehalf the water of hydration.

lama-w n .i, -.-i ,e

9. The method of producing a self-hardening dry powder cementitious material comprising incompletely burning dolomitic limestone to magnesium and calcium oxid to such an extent that but a minor portion of its carbon dioxid remains, 5 with the magnesium oxid resistant to direct hydration and the calcium oxid to the extent burned readily responsive to hydration; subdividing the material into granular form; and imparting water-carrying properties by hydrating the granular material with a just sufiicient amount of solution to obtain a stable dry powder including combined water, said solution including a chemically active substance to react on the material being treated but sufliciently water-dispersed to prevent the formation of oxy-salt products.

10. The method of preparing a cementitious substance from dolomite comprising calcining dolomite at 900 to 1000 C. to an extent to retain five to seven per cent carbonate with magnesium oxid from said calcining resistant to direct hydration, and calcium oxid from said calcining readily responsive to hydration, and hydrating with a chlorid solution sumciently diluted to produce calcium chlorid to prevent the formation of oxychlorid.

11. A dry powdered material of commerce adapted to be combined as an improver in cement operation, said material approximately including magnesium oxid, twenty-two parts; calci- 30 um hydrate, forty parts; calcium carbonate, six parts; magnesium hydrate, one and one-half parts, with absence of chlorid of magnesia and oxychlorid.

CLARENCE a. REX. 35 

